iahphx

Out of curiosity, what is the safety advantage of operating a jetliner under VFR? Wouldn't they be safer, um, using the instruments?

Hartmann

VFR is a set of minimums for the operation of aircraft. The pilots are still using their instruments.

What this means is that the pilots have to be able to accurately see where they are going (even if instruments were to go out) to be allowed to operate the aircraft.

More info here:http://en.wikipedia.org/w/mobileRedi...l_flight_rules

rkkwan

Another flight in the air:

CO1950 LHR 762 - this is a revenue flight with full passenger load

CaptainMiles

You can still use the instruments under VFR. You're just not required to rely on instruments alone.

I think the biggest difference is in who provides the traffic separation.

• Under VFR, the pilot must stay away from clouds and is responsible for separation from other traffic (except in class B airspace, which I don't think exists in Europe). Since they are not in clouds, they can keep away from other traffic by looking out the window. Enroute, the controller provides optional traffic advisories only. Pilots can deviate from their course or altitude for any reason at any time. Normally they would deviate to avoid clouds or traffic, but they can do it for any reason. Pilots do not have to notify the controller of any deviations, but would normally do it as a courtesy -- just as the controller is providing traffic advisories as a courtesy.
• Under IFR, in most controlled airspace controllers are responsible for separation. They tell pilots where to go, and for the most part pilots go where they are told, even if that means going through clouds. Pilots can go through clouds because they don't need to look out the window to stay away from other traffic, as the controller is doing that for them. Pilots don't mind going through clouds because they pose no danger. Exceptions are thunderstorm clouds, but those are typically visible to controllers on radar and they tend to route aircraft around them. Other exceptions are sandstorms, smoke and volcanic ash, and those are not visible to controllers, but they are usually rare and handled on a case by case basis.

Airlines fly under IFR all the time. It appears that there is some airline VFR flying in Europe at this time, due to the extraordinary circumstances there.

I think Europe's idea of operating under VFR is to relieve the controlling agency from the responsibility of sending an aircraft into an ash cloud. If an aircraft flying under VFR rules encounters ash, the airline can't sue the controlling agency claiming that their controllers sent them into ash. Under VFR, the pilot in command was the one choosing the route and altitude, and the controller only provided optional traffic advisories. Any ash encounter would be the pilot's fault.

Or is can be seen another way. VFR gives the pilot more flexibility to choose the route and altitude. If they encounter ash, they can immediately deviate without even asking permission from a controller. When there is a significant risk of ash encounter, and a comparatively low risk of air-to-air collisions, this may make sense from a safety point of view.

I don't think the U.S. Federal Aviation Regulations or the airlines' own ops manuals allow airlines to operate under VFR rules while carrying passengers. Some exceptional waiver would have to be granted. Maybe rules are different in Europe and VFR by airlines is allowed, or maybe the Europeans came up with some emergency waivers for their airlines under the current extraordinary circumstances. Is it just possible that the FAA may not have issued such waivers yet.

rkkwan

CO opearting a 735 this morning to YYT to "rescue" those stuck in Newfoundland due to canceled flights over the past few days.

CO1950 EWR YYT
CO1951 YYT EWR

rlbmorton

Thanks for explaining all this!

rkkwan

CO operated an extra 772 IAH-LHR today, Thurs 4/22... CO1952, at 2p. Only a few empty seats.

Will return on 4/23 at 7a as CO1953.